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How to Solder Copper Pipe

Soldering copper pipe

Date created

Wednesday, 11 May, 2016 - 15:38

Last updated

Wednesday, 11 May, 2016 - 15:38

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Soldering copper pipe is a fairly basic way to join copper pipe and is used in bathroom and kitchen installs, remodels, and renovations. If you are renovating or remodeling your home or adding an other water line to part of your yard or garden, you can run it with copper pipe. We show you how to solder copper pipe and copper to brass fittings using soft solder and silver solder. Know the differences and learn how to use then effectively.
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How To Solder Copper Pipe

Soldering copper pipe is a fairly basic way to join copper pipe and is used in bathroom and kitchen installs, remodels, and renovations. If you are renovating or remodeling your home or adding an other water line to part of your yard or garden, you can run it with copper pipe.

Sizes of copper pipe used in homes

  1. 1/2 inch or 12mm - is the most common copper pipe used to run hot and cold water in a bathroom
  2. 3/2 inch or 15mm - is also common but you will most find it as the water supply line for cold and sometimes hot with 1/2 inch or 12mm tee fitting coming off it leading to different taps or faucets.

Two main types of Solder used

There are 2 main types of solder used to join and seal copper pipes - Silver Solder and Soft Solder (sometimes called silver solder by some people - which can be very confusing). However they are different in the way you use them and they need different flux to install them. I hear you scream - What is Flux? Flux is a paste that is wiped on as you bring the copper join together. When heated it helps the hot solder run into the joint and around the pipe.

Soft Solder

- This is used on copper pipes and copper to brass joints and melts at a much lower temperature than the harder silver solder. You will also find it used on electronic wires and circuits because of it lower temperature requirements.

Pro's

  • Does not need as much heat as silver solder
  • Generally a bit cheaper then silver solder
  • Is available in stick or soft wire form with or with flux inside
  • Easy to use

Con's

  • The copper joints must be very clean of the solder will not take
  • More preparation time is needed to insure a good join and seal

Silver Solder

- This is used on copper pipes and copper to brass fittings, with a hotter temperature needed to melt the silver solder into the joint. Does not always need flux.

Pro's

  • Does not generally need a flux when soldering copper to copper but always use flux when soldering brass and copper together
  • Joints in copper and copper to brass need to be fairly clean, however not as touchy as soft solder
  • Results in a very strong joint in copper and brass joints

Con's

  • A bit more expensive then soft solder
  • Hotter temperature is needed to heat the solder and pipe - not LPG - you will need Mapp or pro Gas with burns hotter to get the job done

Both of these types are valid when soldering your copper and bass fittings and should give a joint that lasts 50 years or more. Preparation is the key to success on all joints whether you choose to use soft or silver solder. A badly prepared joint will give you a lot more trouble than the time it takes to clean it - so it is best to take the time to do it right.

Preparation - The key to Success

To prepare each joint you should first cut your copper pipes to size with a pipe cutter or hack saw and fit it all together to make sure that it is right before you solder. Then clean each joint and fitting with 180 to 240 grit sand paper until it is bright and clean and free from other contaminates. For soft solder you should make sure it is very clean and then wipe or brush on the soft solder flux and reassemble the joint ready for heating and adding the solder. For silver solder clean well until the joint is bright and then wipe with sliver solder flux if you like but it is only needed when jointing copper to brass. Then your joint should be ready for heating.

Heating - soldering copper and brass fittings

Soft Solder Heat

When heating your copper pipes and fitting, make sure it is safe manner. Always have a bucket of water ready is case of fire. Also make sure the flame is not directed towards timber, electrical wires, and any flammable materials. Heat the joint or fitting heating the thickest area first. When you see the flame start to turn green It should be ready to feed in the solder. Make sure you run the melted solder around the full joint. - Job done - always check your work and test it under full water pressure.

Silver Solder

Again heat in a safe manner looking out for timber, electrical, and flammables. Remember Silver solder needs more heat - so heat the fitting, pipe or joint until it starts to glow red and then feed in the stick of silver solder checking it melts and runs on the pipe or fitting. When heating brass and copper the brass will require more heat so concentrate the flame on the brass until it starts to glow red. Then run the solder right around the joint - job done - check your work.

Soldering copper and brass plumbing fittings are fairly simple if you take care on the details and safety. Both solder types will give a good joint and seal that will last for many years. I mostly use the silver solder method because it is simple and I personally find that I get no leaks and I have not had a pipe leak when tested with silver solder. However, both methods work and the soft solder is great when you can't use a lot of heat.